Avaricta, Gitaxian Sective

Flying, deathrouch
When Avaricta attacks alone, each creature defending player control gets -X/-1 until the end of their turn, where X is the number of creatures you control.
Pact (You can have two commanders if both have pact. If the two commanders share a creature type, they cost {x} less to cast, where X is number of times the commander's been cast.)